Validity of reported indicators of pesticide exposure and relevance for cytotoxic and genotoxic effects on buccal cells.

Higher rates of nuclear anomalies in buccal cells of coffee workers exposed to pesticides in comparison to their unexposed peers were detected in our field study. Here, we extend our findings by examining other exposure indicators in this sample. Occupational exposure of 38 exposed and 33 non-exposed farmworkers was assessed as exposure days in the last month (0-25 days) and as years of exposure (0-47 years). Genotoxic and cytotoxic markers in buccal cells were analysed following standard procedures for buccal micronucleus cytome assay. Both exposure markers were associated with a higher frequency of nuclear anomalies with odds ratios more than 1. After restricting the analysis to the exposed workers only, this association remained only with the marker of recent exposure. In a secondary analysis also environmental exposure defined as proximity of the home to the nearest sprayed field (distance <1000 m) was assessed. Proximity led to increased rates (with odds ratios more than 3) of genotoxic but not cytotoxic nuclear anomalies. Reported recent frequency and intensity of pesticide use and application are a valid exposure marker relevant for cytological pathologies in the buccal mucosa. The exposure metric for environmental exposure was rather crude and confounding by some unmeasured factor cannot be fully excluded. Nevertheless, simple exposure indicators that can even be obtained under rather difficult field conditions do provide health-relevant and valid information.